Onda is a Java application that compresses 16-bit and 24-bit AIFF and WAVE audio files using the Onda lossless audio compression (LAC) algorithm. The Onda algorithm doesn't perform as well as some other open-source LAC algorithms in terms of either speed or compression ratio; its virtue, if it can be said to have one, is that it is easy to understand and to implement, involving no mathematics beyond a bit of arithmetic.

The motivation for publishing the Onda algorithm is that there may be circumstances in which a mediocre but simple LAC algorithm that's easy to implement is preferable to a good but complex algorithm. There is a diminishing return on the complexity of LAC algorithms; each extra percentage point of compression becomes increasingly difficult to achieve. The Onda algorithm is content with the easy pickings: it gives up the struggle for extra compression when the going gets tough, with the expectation that its less-than-stellar performance will be sufficient for some purposes.

Onda is free software, distributed under version 3 of the GNU General Public License.


The current version of Onda is 4.2 (2017-11-04).

Blank Aspect NLF (Nested-List File) library

NLF (Nested-List File) format is a general, chunk-based file metaformat for binary data that is used by Onda as the metaformat for its compressed files. The Blank Aspect NLF library is a Java package, uk.blankaspect.common.nlf, whose classes can be used to read, write and manipulate documents in NLF format. It is available separately from the Onda application.

The Blank Aspect NLF library is distributed under version 3 of the GNU General Public License.